If you had one shot or one opportunity to seize everything you ever wanted, would you capture it or just let it slip? That's the dilemma facing Jimmy Smith Jr. a.k.a. B-Rabbit (Eminem), an aspiring rapper who by day works in a car parts factory and by night takes part in freestyle rap battles.

However, chronic stage fright is just the beginning of Jimmy's problems as he deals with his alcoholic mother (Kim Basinger), her abusive boyfriend (Michael Shannon), a complicated love interest (Brittany Murphy) and a fellow rap crew led by a hostile and violent rival (Anthony Mackie).

With sweaty palms, weak knees and heavy arms, can B-Rabbit overcome adversity and his own self-doubt and lose himself in the music?